Lightning-arrester connection.



No. 840,036. PATENTED JAN. 1, 1907.

E. A. BALDWIN.

LIGHTNING ARRESTER CONNECTION. APPLICATION FILED we. a, 1904.

W INVENTOH 1 I I Edward fL-Baldwm,

' derground-cable work and in systems made tween conductors isparticularly trouble- 'untii the insulation fails and a short circuitUNITED srArEs PATENT 'GFFIGE EDW'ARD A. BALDWIN. OF SCHENECTADY, NEWYORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

LlGHTNING-ARRESTER CONNECTION.

. Specification of Letters Patent.

\ Patented Jan. 1, 1807.

Application filed August 8, 1904. Serial No. 219,858-

To all whom, it may concern:

Be it known that I, EDWARD A. BALDWIN, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Lightning-ArresterConnections, of which the following is a specification.

Static charges on alternating-current-transmission lines arise from twodistinct causes first, from lightning discharges and inductive efi'ectsdue to atmospheric conditions, and, second, from resonance effectsarising in the line conductors themselves. It is customany to protectagainst atmospheric discharges by connecting lightning-arresters betweeneach line conductor and ground. This arrangement, however, does notfully protect the system from abnormal voltages existing between lineconductors as the result of resonance. Abnormal voltages due toresonance appear .to be most common in circuits made up partly ofcapacities and partly of reactances and in long-distancetransmissionlines. In extreme cases the abnormal v0l-, tags may beseveral times the normal working voltage of the system; but as thefrequency is many times the normal frequency the central-stationinstruments will not indicate in any way this abnormal voltage. Ingeneral, no indication of its presence is given between iine conductorsis formed. In unup partly of underground cables andfpartlyoioverheadmvires this static discharge besome, because of the relativelysmall distance between the underground cables and the consequentliability of a destructive arc.

It is the object of the present invention to provide means forprotecting the transmission-line from abnormal voltages arising from anysource, whether from atmospheric conditions or from resonance. a

My invention will be readily understood by reference to the followingdescription, taken in connection with the drawings forming a part of thespecification. 1 shows the general arrangement of thelightning-arresters or resistance devices. Fig. 2 shows the same arranement diagrammaticallv for convenience 0 reference.

The hinhtningmrresters shown are of the No. 669,155, March5, 1901.

general type described in .the patent to Wirt, This invention, however,is not limited to the particular form of arrester including anon-inductive resistance and spark-gaps, as shown in the above namedpatent, but may be any formwhich offers a suitable impedance to the flowof ouring a voltage drop in the ground connection when current flowstherethrough.

The arresters shown in Fig. l consist, es-

-sentially, of an insulating base, on which are arranged two carbonresistance-rods and a plurality of metallic cylinders, between whichsparks-gap are formed. The number of carbon rods and the number ofspark-gaps for each unit may be increased to suit the particular voltageused for the line, and the invention is not limited to the particularnumber shown. Likewise the number of unitsmay be increased at will. Theconductors 1', 2, and 3 represent the three linewires of the polyphasetransmission-line. Between the conductors 1 and 3 is connected theresistance device composed or arresters i and 5.

The arresters 6 and 7 are connected between conductors 1 and 2, and thearresters 8 and 9 between the conductors 2 and 3. Between the arresters4 and 5 a connection leads to a similar arrester 12, the other end ofwhich is connected to ground. Similarly a connection from between thearr-esters 6 and,

provided a lurality of paths between each pair. of con uctors, thesepaths serving for the equalization of static charges between conductors.Thus between conductor 1 and ground there is a path through arresters 7and 11 and a parallel path through arresters 4t and 12, while betweenconductors 1 and 2 there is one path through arresters 7 and 6 andanother path through arresters 4, 12, 11, and 6, as Well as others,which are apparent from the diagram; The arrangement described providesthe same number of arresters or resistance units between each conducetor' and ground as between one conductor and another, and as part of thearresters are used both in the ground connection andgin the connectionbetween conductors the arrangement described furnishes an efficient lineconductors consisting of resistance devices connected across each phase,and means connected with each of said devices for providing aresistance-path'to ground.

2. Means for protecting line conductors of electric circuits, consistingof a resistance device connected between each two conductors of saidline, said device including a spark-gap, 3 5

line comprising three conductors, of three re- 40 sistance devicesarranged in delta between the three conductors, connectionsfrom thecenter of each side of the delta to other resistance devices, and meansfor connecting said last-named resistance devices to ground.

4. The combination with aipolyphase transmission-line of means forprotecting the line conductors, consisting of resistance devicesconnected across each phase, and means connected with the center of eachresistance device for providinga resistance -path to ground, said meanshaving substantially onehalf the resistance of one of said resistancedevices.

- 5. The combination with the conductors of analternating-current-transmission line, of means for providing twopermanent resistance-paths between each conductor and ground, said meansproviding a plurality'of resistance-paths between conductors.

In witness whereof I have hereunto set my hand this 6th day of August,1904. r

I EDWARD A. BALDWIN. Witnesses:

BENJAMIN B. HULL, HELEN ORFoRn.

